2007-2008 Science Olympiad Lightest Bridge

First we built this bridge weighted 31 grams. It only supports 15 Kg. It bends badly above 15 Kg.
Score: 1500/31 + 1500/10 = 198




Built another one to support more than 20 kg. This one weights 49 grams.

Score: 1500/49 + 1500/10 + 500 (bonus) = 680